Well pumping system



R. F. GILCHRIST WELL PUMPING SYSTEM Filed Aug. 11, 1958 FIG. I.

June 28, 1960 INVENTOR. BY W &

. ATTORNEY ROBERT E G/LCHRIS T FIG. 3.

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WELL PUMPING SYSTEM Robert F. Gilchrist, 1629 Britain, Wichita Falls, Tex. Filed Aug. 11, 1958, Ser. No. 754,225

3 Claims. (Cl. 103-49) This invention relates generally to oil field equipment and more particularly to a system for operating oil well pumping units.

A primary object of this invention is-to provide an improved system for simultaneously operating two oil well pumping units of the walking beam type.

Another object is to provide a method and an apparatus for simultaneously operating tWo pumping units having a counterweight by the employment of a reciproeating cable system to operate the power stroke of the pump.

A further object is to provide a pump operated cable system which automatically and hydraulically reverses itself on each stroke of operation.

Another object is to provide a unitary operating system for two spaced oil well pumping uni-ts having facing counterweights, which system is operated by a reversing stroke cable to apply a power stroke to each pumping unit in alternating sequence.

And another object is to provide an improved hydraulic system for accomplishing the reversing power stroke for the pumping units.

These and other objects and advantages of this inven-' tion will become apparent from an examination of the following specification and drawing in which:

Figure 1 represents a side elevational outline view of the complete assembly of this invention.

Figure 2 is a plan view of hydraulic system piping and components employed in the method and apparatus of Figure 1.

Figure 3 is an enlarged longitudinal sectional view of Patented June 28, 1960 caused to be rotated upward about its pivot by a lever arm structure 17, to which the cable 6 is attached at 18. In Figure l we will assume that pumping unit 3 has just completed its down or return stroke and that pumping unit 4 has just completed its up or lift stroke. Cable 6 until this moment has been relaxed and now becomes taut as the plunger 20 of cylinder 21 of the hydraulic unit 5 begins its stroke toward the other pumping unit 4. At this point the tension in cable 6 is converted into torque at point 18 and the horsehead is moved upward lifting the pump sucker rod 12 and pumping oil into a storage tank piping system fitting indicated at 23. As soon as the plunger 20 has reached its full stroke, the fluid to cylinder 21 reverses direction and plunger 21 immediately begins to move to the left. Upon this occurrence, the cable 6 slackens and the horsehead 10, which acts as a counterweight, descends and causes beam to move about its pivot 16 and permits the sucker rod and its attached pump plunger to rea fragmentary section of the main hydraulic cylinder of this invention.

Figure 4 is an enlarged longitudinal sectional view of one direction control valve for the cylinder of Figure 3.

Figure 5 is a perspective view of the detached barrel assembly of the mechanical reversing valve employed in the system of Figure 2.

Figure 6 is a side elevational view of the direction porting section of the barrel assembly of Figure 5.

Referring now to the characters of reference on the drawing it will be observed that the complete assembly of the apparatus of this invention identified generally at 2, consists basically of a pair of oil well pumping units 3 and 4, a centrally located reciprocating hydraulic power unit 5 and a pair of cables 6 and 7 in operating relation between the power unit 5 and the pumping units 3 and 4 respectively. This invention also relates to the method by which this apparatus operates to produce oil from the ground. It is preferred to position the pumping units 3 and 4 so that they face each other and so that their horseheads 10, which also serve as weights, are on the side nearest the center. A short length of flexible cable 11, or bridle, lays over the outer curved edge of the horsehead 10 and this cable 11 is directly connected to a sucker rod 12 which extends into and extracts oil from an oil well tubing 14. The horsehead 10 is at the extreme end of a walking beam 15 which is pivoted at 16 and which is turn to its lower position in preparation for the next subsequent power stroke (upward movement). As the cable 6 is applying a power stroke to the pumping unit 3, the opposite cable 7 is relaxed and permits pumping unit 4 to function through its return stroke. It will be observed that by this method of operation there will be a continuous flow of oil into the storage tank and that there will be a constant utilization of input power and a smaller demand load than in certain earlier multiple pumping systems where the pressure stroke is applied toall pumps simultaneously. Also, it should be noted that in Patent No. 1,034,698, to Davisson, compressed air was the motivating power whereas in the instant invention a non-compressible hydraulic fluid is the power agent, and with a liquid there is no compressibility to accommodate override and hence a special reversing mechanism must be employed.

This operating and reversing mechanism may be observed in Figures 2-6 wherein the power unit 5 is basically comprised of a motor 25 (which may be electric or other power) operating a belt drive 26 which in turn operates an hydraulic pump 27 at a constant speed to provide an outlet pressure as indicated by gage 28 in line 29 to manifold 30 and thence to lines 31 and 32 of direction valves 33 and 34, respectively, and through line 36 to reversing valve 35. Return lines 374t) connect the valves 33-35 with accumulator 41 and line 42 connects the accumulator with the intake side of the pump 27. In a system of intervalve control piping, the line 44 connects port 45 of valve 35 with ports 46 and 47 of valves 33 and 34 and line 49 connects the port 50 of valve 35 with the ports 51 and 52 of the valves 33 and 34.

When the plunger 20 of cylinder 21 in Figure 3 is moving in the direction of the arrow, and has just come into contact with the vertical lever 60 which is pivoted at 61 to a rigid beam 62 attached to cap 63 of the cylinder 21, fluid under pressure is directed from pressure line 36 through groove 72 (Figure 6) in barrel 71 to outlet line 45 and thence into line 44 to port 46 of direction valve 33. Pressure entering port 46 has caused plunger 73 to move to the right in cylinder 74 until it has met stop 75 at which point the groove 76 aligns with port 77 of pressure line 31 and with port 78 which directs fluid into manifold channel 79 and out through port 80 and into line 81 which feeds directly into cylinder 21 to apply pressure to move piston 64 to the right as shown at this instant. At the same time that pressurized fluid from line 31 is passing through valve 33 to line 81, exhaust fluid is passing from the opposite end of cylinder 21 out through line 82, through valve 34 and line 38 into return line 40 to accumulator 41. And the control line 49 from port 51 to port 50 will, at this same time, complete the fluid circui-t through slot 84 of barrel 71 to line 39 and back to the accumulator 41 through line 40. Thus, it will be observed that the exhaust from both the power circuit (line 31) and the control circuit (line 44) are redirected to the accumulator during one phase of the operating cycle.

Any further movement of piston 64 and plunger 20 in the direction shown will trip the lever 60 and by its pivotal connection 65 cause rod 66 to move to the left and carry bushing 67 with it, since the rod 66 passes completely through the bushing 67 and is attached thereto by set screw 68. Now since bushing 67 is journalled in lever arm 69 and lever arm 69 is rigidly attached to barrel shaft 70, the barrel 71 will rotate and move from one position to a second position with movement of rod 66.

With the barrel in its second position, pressurized fluid will then be directed from the pressure line 36 through groove 85 to line 50 and thence through line 49A to port 52 to move the piston 73 of valve 34 over against the other stop 86 and thus align groove 76 with ports 87, 88 and 80. This action takes place simultaneously in both valves 33 and 34, and to avoid additional drawings and numbering, the internal parts of both valves will be referred to be identical reference numbers, and the external parts will be identified relative to valve 34 by the suffix A where their function is better identified by showing a correlation with valve 33.

A by-pass line 90 has been placed in direct connection with both pressure line 30 and accumulator outlet line 91, and pressure gage 28 and speed control valve 92 are located in this line. By opening valve 92, the outlet pressure in line 30 is reduced without changing the speed of motor 25.

The rapid trip over of lever 69 and the consequent change of the application of pressurized fluid from the left end of cylinder 21 to the opposite end of the cylinder is necessary because there is no over travel in devices using a non-compressible fluid such as hydraulic oil in contrast with the use of compressed air. Hence it was necessary to devise an apparatus to mechanically reverse the direction of the application of power before shutting.

off the fluid in the first direction. This has been accomplished by the devices shown and described in Figures 2- 7, which in combination with its application and installation as shown in Figure 1 will provide an efficient, economical and useful method and apparatus for the continuous removal of oil from a low pressure underground oil reservoir.

The invention is not limited to the exemplary construction herein shown and described, but may be made in many ways within the scope of the appended claims.

What is claimed is:

1. An apparatus for the power operation of two spaced walking beam oil well pumping units wherein the horseheads thereof are facing each other and wherein the ends of the Walking beams opposite the horseheads have rigid depending lever arms, said apparatus comprising: a cable attached in operating relation to the lower end of the lever arm of each said pumping unit, said pumping units being operated by a pull in one direction only by said cable, a horizontal reciprocating power unit located between said pumping units, and means to connect said power unit in operating relation to each said cable to apply a pull to each cable and operate each pumping unit.

2. An apparatus for the power operation of two spaced walking beam oil well pumping units wherein the horseheads thereof are facing each other and wherein the ends of the walking beams opposite the horseheads have rigid depending lever arms, said apparatus comprising: a cable attached in operating relation to the lower end of the lever arm of each pumping unit, said pumping units being operated by a pull in one direction only by said cable, a power unit located in the vicinity of said pumping units, and means to connect said power unit in operating rela' tion to each cable to apply a pull to each cable in sequence and operate each pumping unit in sequence.

3. An apparatus for the continuous removal of oil from an underground reservoir, comprising: a plurality of reciprocating oil well pumping units installed above and in operating relation with said reservoir, each pumping unit having an up movement power stroke and a down movement return stroke, said units being counterweighted to automatically move down and through their return stroke upon completion of the power stroke, and a lever attached to said pumping unit and adapted to apply an up movement power stroke thereto upon the application of a pull on said lever, and a horizontal reciprocating power unit located among said pumping units, a cable connected to each pumping unit lever, and means in said power unit to apply a pull to each cable in sequence to thereby operate each pumping unit in sequence and provide a continuous removal of oil from the reservoir. 

